The present invention relates to an apparatus for aerating water, and includes a flexible hose of rubber or a rubber-like material that can be disposed in the water and the wall of which is provided with a perforation, fine slits, openings, or the like via which the air can escape into the water, whereby a tubular connector is introduced into one end of the hose, and air can be supplied to the hose via the tubular connector.
With a known, frequently used water aerator, the hose is disposed on a support tube (see, for example, DE 37 00 038 C2). The hose has a slightly larger diameter than does the support tube. The air is conveyed between the support tube and the hose. The air expands the hose and raises it from the support tube. In this connection, the slits in the hose open, and the air escapes into the water. When the apparatus is in a state of rest and is not supplied with compressed air, the hose is supported upon the tube and the slits are again closed.
To simplify the construction of the water aerator, but also for it to be more flexible during installation in the environment in which gas is to be introduced, which environment can, for example, be a clarifying or settling tank, or also an open, natural body of water having irregular, “soft” boundaries, and finally also in order to reduce the flow resistance of the air within the aerator, apparatus of the aforementioned type have been proposed according to which a support tube is eliminated (German patent application DE 102 03 780.9, which was not yet published at the time of the filing of the priority application corresponding to this application). Also with these apparatus, a reinforcing element that extends parallel to the hose is associated therewith to prevent too great of a deformation, especially a bending, of the hose as a consequence of water flows and buoyancy, and hence an adverse effect upon the introduction of gas. Such a reinforcing element can be secured to the outside on the hose, for example in the form of a profiled element. However, the reinforcing element can also be disposed within the hose, whereby its circumference, in contrast to the support tube described above, is, however, significantly less than the circumference of the hose. Such an element can, for example, be a round rod. A particularly advantageous reinforcing element is one of a solid, yet flexible material in the form of a strip or slat having a flat, rectangular cross-section, and which is disposed within the hose in such a way that the longer sides of the cross-section are vertical or upright. This element offers high rigidity against deformation due to buoyancy forces, yet permits horizontal movements and deformations of the hose as a consequence of water flows without resulting in bending that is too sharp. With these aeration elements, when the hose is in a state of rest, and is not supplied with compressed air, it is pressed flat together by the pressure of the surrounding water, and is thus sealed relative to the penetration of water.
With the above-described apparatus with a support tube, the supply of air is effected by a tubular connector that is inserted into the open end of the hose, whereby the tubular connector and the support tube have the same diameter, and the hose is fixedly clamped upon the connector by means of a clamp (DE 37 00 038 C2). A corresponding manner of construction would lead to problems for an apparatus not having a support tube due to the flat pressing-together of the hose in a state of rest. A transition zone would be formed between the cylindrical portion formed by the tubular connector and the flat portion; in this transition zone, portions of the hose would be subjected to high mechanical stresses, especially due to bending or deflection at the edges of the tubular connector. Furthermore, there is no seal in this transition zone in a state of rest, so that it must remain free of slits, and thus cannot be used for aeration.
It is therefore an object of the present invention, for an apparatus of the aforementioned general type, to provide a connection for the air supply in a form that is suitable for the type of construction where no support tube is provided.